I have a problem working with the Fn hotkeys on my brand new laptop Asus. I cannot change my volume, screen brightness, keyboard back light and other minor functions.
I have tested many possible solutions, but without any sucess.
Thank you!

Well, assuming you're using 12.04 LTS, the hot key setting is more included with the default operating system. I has an ASUS eeePC 900 and when I went from Windows XP to Windows 7, I lost functionality of my function keys as you have. My recommendation, is to simply goto: System Settings > Keyboard > Shortcuts (This is a tab located at the top.) and then create a custom short-cut as the computer has listed on the keyboard for the functions you desire. That would seem to be the easiest way, I don't know about keyboard backlight however, that sounds as if it would be managed with an included tool made specifically for the computer, not included with the operating system in question.